RF plasma-deposited surfaces provide a model of complex surfaces and exhibitmany of the problems encountered in the analysis of biological systems, for example the presence of many different functional groups and differing degrees of crosslinking. A large variety of surfaces can be produced via RF plasma deposition, ranging from little structural rearrangement of the monomer unit to severe rearrangement. The films will be used to assess the capability of SIMS to probe crosslinking degree, the ability of SIMS and multivariate statistics to assess quantitatively one functional group in the presence of others, and to optimize derivatization protocols previously developed in this lab.